It's not that the distribution is static, it's that the distribution is computed once when the model is built and then becomes outdated if the UI is changed as the model is being used. Many places have different timelines for updating machine-learned models vs. deploying new frontend code; anywhere from "a month" to "we'll rebuild it manually when we need to" is typical for the former, while good engineering shops do weekly, biweekly, daily, or sometimes even hourly for frontend changes.